A collaborative research team from the Geological Survey of Denmark and Greenland (GEUS) in Copenhagen, Cardiff University in Wales, Lund University in Sweden and the Institute of Planetary Science in Moscow have discovered the remnants of a giant 3 billion year old impact in the Maniitsoq area of West Greenland. The oldest known impact structure so far on the Earth is the 300 km wide Vredefort Structure in South Africa dated at 2 Ga.
Although almost all the external evidences of the impact have been eroded away, the effects of the intense shock metamorphic effects have been retained at deeper levels of the crust. Painstaking research work conducted by the collaborating agencies over the last three years has resulted in gathering sufficient evidences to convince the scientific community of this 3 Ga old (100 km) circular major impact feature of the earth. For further details on this Maniitsoq structure readers may consult the following sources:
(i) http://www.geus.dk/cgi-bin/webbasen nyt uk pl? id = 1340629662 % 7 Ccgifunction = form
(ii) Paper in Earth and Planetary Sciences Letters: http://dx.doi.org/10.1016/j.epsi2012.04.026
MSR/3 Sept. 2012